1. GSM Short Message Service

2. GSM Short Message Service
Can contain up to 140 octets, or 160 char.
To allow messages longer than 160 char.
SMS concatenation
SMS compression
SDCCH signaling channel (SDCCH (Standalone DCCH) for signaling (authentication, registration, etc)
Two type of GSM SMS
Cell broadcast service
Point-to-point service

3. 12.1 SMS Architecture
Figure 12.1 GSM short message service network architecture

4. 12.2 SMS Protocol Hierarchy
Figure 12.2 SMS MS-MSC protocol hierarchy (mobile origination)

5. 12.2 SMS Protocol Hierarchy
Short Message Transfer Layer
Provides services to transfer SM-AL short msg.
Generate a reference number SMI (short message identifier)
SM-AL SMI is not carried between the MS and SM-SC
Four types of transfer protocol data units (TPDUs)
SMS-SUBMIT
SMS-DELIVER
SMS-STATUS-REPORT
SMS-COMMAND

6. 12.2 SMS Protocol Hierarchy
Short Message Relay Layer
Provides services to transfer TPDUs and delivery reports for SM-TL
Generate SM-RL SMI for every short message
SM-RL SMI is mapped to and from SM-TL SMI
SM-RL SMI at the MS is not carried at the peer entity in the SM-SC
SM-RP consists of the following RPDU types:
RP-DATA
RP-SM-MEMORY-AVAILABLE
RP-ACK
RP-ERROR

7. 12.2 SMS Protocol Hierarchy
Connection Management Sublayer
Provides services to support the SM-RL
MS has two SMC entities
MS-originated (MO) short message service
MS-terminated (MT) short message service
SM-CP consists of following protocol elements
CP-DATA
CP-ACK
CP-ERROR
MNSMS-ESTablish
To establish an MM-connection and transfer RPDU on that establish
MNSMS-DATA
Transfer an RPDU on MM-connection
MNSMS-RELease
MNSMS-ABORT
MNSMS-ERROR

8. 12.3 Mobile-Originated Messaging
The logical message path is :
MS -> originating MSC -> IWMSC -> SM-SC
Figure 12.3 Mobile-originated short messaging (part 1)

9. 12.3 Mobile-Originated Messaging
Figure 12.4 MM-connection establish for mobile-originated short messaging

10. 12.3 Mobile-Originated Messaging
Figure 12.5 Mobile-originated short messaging (part 2)

11. 12.3 Mobile-Originated Messaging
Figure 12.6 Mobile-originated short messaging (part 3)

12. 12.4 Mobile-Terminated Messaging
The logical message path is :
SM-SC -> GMSC -> terminating MSC -> MS
Figure 12.7 Mobile-terminated short messaging (part 1)

13. 12.4 Mobile-Terminated Messaging
Figure 12.8 Mobile-terminated short messaging (part2)

14. 12.4 Mobile-Terminated Messaging
Figure 12.9 Mobile-terminated short messaging (part 3)